[Keith Seymore]

Cost and function.

The leaf spring not only carries the load, but also provides the rear axle locating device, all in one.

With coils, you have to have the spring (to carry the load) but then additional linkages to position the axle. It's more expensive to tool and produce.

Additionally, while coil springs provide a better ride - which is fine for passenger carrying vehicles - leaf springs allow for a higher load capacity, which is what you would want for a pickup truck.

It's actually an excellent question, and one that we wrestle with every time we start a new vehicle architecture.

K